1. Technical Field of the Invention
This invention relates to Condensation Products useful in the manufacture of flexible polyurethane foam. More particularly, this invention relates to the preparation of Condensation Products from a particular class of polymeric diamines and polyethylene terephthalate and to the use of the thus prepared Condensation Products in the manufacture of flexible polyurethane foam.
The invention is based upon the discovery that certain water soluble polymeric poly(oxypropylene-oxyethylene-oxypropylene) diamines, as herein defined, which can be reacted with scrap polyethylene terephthalate to provide condensation products, can be used in the manufacture of flexible polyurethane foam. It is also based upon the discovery that the use of such Condensation Products results in the formation of flexible urethane foam having improved physical properties.
2. Prior Art
When terephalic acid is reacted with a diamine, the representative reaction product is a water-insoluble liquid. When terephthalic acid (normally in the form of the dimethyl ester, dimethyl terephthalate, is reacted with a glycol such as ethylene glycol, water-insoluble polymers are formed, characterized by the formula: ##STR3## wherein n is a number having a value of about 50 to about 500.
It is known to react dibasic acids such as adipic acid, azelaic acid, terephthalic acid, polymers of fatty acids, etc. with diamines of the formula: ##STR4## wherein x is a number having a value of 0 to 4 to form reaction products useful in the preparation of coatings and adhesives as shown, for example, by U.S. Pat. No. 4,128,525 and U.S. Pat. No. 4,167,498.
An extensive body of technical knowledge has arisen relating to the preparation of solid polyethylene terephthalate from suitable monomers such as ethylene glycol and dimethylterephthalate.
Polyethylene terephalate is widely used in the manufacture of beverage bottles. The disposal of used bottles in an environmentally acceptable manner presents a major problem. One proposed solution has been to convert the used polymer into an unsaturated polyester that can be used to make moldings such as boat hulls (Plastics Technology, September 1981). The used bottles are reported to have been used as raw materials in the manufacture of industrial strappings, fiber fill for pillows, sleeping bags and the like, synthetic lumber and corrugated rubber (C&E News, Jan. 5, 1981, p. 30).
Polyoxypropylene polyether polyols are widely used in the preparation of flexible polyurethane foam by the reaction of the polyol with an organic polyisocyanate in the presence of a catalyst and other conventional ingredients, such as blowing agents, foam stabilizers, etc.
As shown, for example, by Cuscurida et al. U.S. Pat. No. 4,296,213, it is known to use low molecular weight hydroxy amines for the preparation of chain extenders for use in flexible polyurethane foam. In accordance with the Cuscurida et al. patent, the low molecular weight hydroxy amine is initially reacted with a minor amount of an organic polyisocyanate in the presence of a polyoxypropylene polyether polyol to form a polymer polyol which is thereafter used as a chain extender in the manufacture of a flexible polyurethane foam.